Generally described, computing devices utilize a communication network, or a series of communication networks, to exchange data. Companies and organizations operate computer networks that interconnect a number of computing devices to support operations or provide services to third parties. The computing systems can be located in a single geographic location or located in multiple, distinct geographic locations (e.g., interconnected via private or public communication networks). Specifically, data centers or data processing centers, herein generally referred to as “data centers,” may include a number of interconnected computing systems to provide computing resources to users of the data center. The data centers may be private data centers operated on behalf of an organization or public data centers operated on behalf, or for the benefit of, the general public.
Existing routing and addressing technologies can enable multiple data centers to provide similar or identical content to client computing devices. In some instances, each data center providing a set of content may be referred to as a point-of-presence (“POP”) for a content delivery system (or other organization) providing the content. Content delivery systems (sometimes referred to as “content delivery networks,” or “CDNs”) often prefer to connect users to a geographically-nearby POP, as such connections are commonly quicker and more reliable than connections between a user and a geographically-distant POP. Accordingly, a content delivery system can maintain POPs over a wide area (or worldwide). Thereafter, requests for content from the content delivery system can be routed to a nearby POP for fulfillment.
Each POP may be associated with an address on a computing network, such as an Internet Protocol (IP) address. However, requests for content are generally addressed to a human-readable identifier, such as a universal resource identifier (URI) or domain name. To enable use of human-readable identifiers in accessing content, a client computing device can interact with a Domain Name System (DNS) that operates to resolve a domain name into a corresponding network address (e.g., IP address). Typically, a CDN is associated with one or more domain names, and an operator of CDN will have authority to alter DNS records specifying IP addresses to which those domain names resolve. Thus, the operator of a CDN can utilize DNS records to control how requests to access content of the CDN are routed to POPs.